This invention relates generally to slot wedge assemblies for a dynamoelectric machine and, more particularly, relates to a slot wedge assembly for retaining a winding element in a winding slot of a dynamoelectric machine core member.
Conventionally, windings located in the slot portion of a generator rotor or stator are maintained in place by wedges located end-to-end and dovetailed against radial movement. These wedges serve to hold the windings secure against substantial electromagnetic and vibratory forces which tend to dislodge and move the windings whereby the life of the windings, wedges, and core member are reduced. To reduce the amount of potential movement within the slot, the wedges and slots are carefully machined to obtain a tight fit between the components for preventing axial displacement or rattling. Owing to the hostile operating environment, creepage and shrink of the slot components is common whereby any gaps and variances between the slot components may become magnified. The creepage and shrink tends to loosen the components and magnify any gaps or variances where the components are influenced by the electromagnetic and vibratory forces despite the careful machining. It is therefore known in the art to incorporate a resilient member, located between the wedge and winding, to aide in maintaining the wedge and winding in tight fitting arrangement within the slot despite any gaps or variances which may be present or arise. The use of the resilient member causes the wedge to be biased into positive contact with the engaging surfaces of the wedge receiving portion of the slot while the winding is secured under load within the slot thereunder.
While the employment of the resilient member is a step in solving the problem of loading and movement within the slot over the short term, movement none-the-less continues to exist owing to the limited loading ability of the resilient member over time. Accordingly, a need exists to reduce tolerance requirements while providing a simplified yet dependable method of compensating for variances and gaps between the slot component parts over the continued operation of the dynamoelectric machine.
As a result of these excising needs, it is an object of the present invention to provide an improved wedging arrangement for securing a winding in the slot of a core.
Another object of the invention is to provide a wedging arrangement which compensates for variations and gaps among the slot component parts over an extended period of time.
Yet another object of the invention is to provide an improved wedging arrangement which is easy to assemble and yet will not come out of the slot inadvertently after assembly.